There exist a number of prior art glasses frames which allow users to change the lenses thereof Examples include U.S. Pat. No. 4,504,127 to Cottet, U.S. Pat. No. 4,523,819 to Dianitsch et al., U.S. Pat. No. 5,900,922 to Moore, U.S. Pat. No. 6,234,627 to Agnoli, U.S. Pat. No. RE37,523 to Bondet, U.S. Pat. No. 6,517,202 to Huang, U.S. Pat. No. 6,533,412 to Wang et al., U.S. Pat. No. 7,316,479 to Matera, and U.S. Pat. No. 7,329,000 to Actis-Datta, and U.S. Patent Application Publication No. 2005/0179856 to Van Atta et al.
The inventor has determined a need for improved apparatus and methods for providing interchangeable lenses for clip-on glasses.